Device to extract physiological information and method therefor

ABSTRACT

A device to extract physiological information has at least one laser emitter. At least one optical detector is used to detect a change in optical power absorption. The laser emitter and optical detector are wire bonded into a chip scale module.

RELATED APPLICATIONS

This patent application is related to U.S. Provisional Application No.62/458,465 filed Feb. 13, 2017, entitled “HEART WAVEFORM & BLOOD ALCOHOLEXTRACTION FROM A DISTANCE” in the name of the same inventor, and whichis incorporated herein by reference in its entirety. The present patentapplication claims the benefit under 35 U.S.C § 119(e).

TECHNICAL FIELD

The present application relates generally to the technical field ofmedical and wearable devices, and more specifically, to the technicalfield of a device using laser emitters to extract physiologicalinformation from a user.

BACKGROUND

Many medical and/or wearable devices utilize optical means coupled tothe skin to extract physiological information from a living subject. Forexample, a fitness tracker utilizes the change in optical power as lightabsorption varies with blood flow through arteries and veins. Heart rateinformation is then used to measure stress (HRV), fatigue, activities orillness. Similar means exist to determine other factors such asoxygenation, blood alcohol content, glucose, keytones, and the like.

Many medical and wearable devices utilize optical emitters and opticaldetectors such as photodetectors as the optical means to extractphysiological information. Unfortunately, these types of devices havehistorically had several significant problems. Medical and wearabledevices utilizing optical emitters and optical detectors generally donot work more than 1-2 mm away from the skin or the wearer. Further,optical detectors such as photodetectors are easily saturated by sidelight. For example, when photodetectors are moved away from the skin ofthe wearer, side light may be detected by the photodetectors rather thanjust the reflected light. As a result, the photodetectors may saturateor have a limited operation range. To overcome this, the opticalemitters must be physically and optically separated by a barrier fromthe optical detector resulting in a much larger surface area for theassembly and the photodetector kept close to the skin to ensure lightfrom the outside environment and side light from emitters is blocked.

Another issue is that medical and wearable devices generally use lightemitting diode emitters. The light emitting diodes generate widelyscattered light requiring optics that force deep recessing of 5 mm ormore into typical form factors and often external lensing. However, thelight emitting diodes do not elicit reflections from more than 1-2 mmaway strong enough to measure. Thus, the result is that bands or watcheswhich extract information like heart rate using light emitting diodeshave to be pulled very tight against the skin of the wearer and formfactors such as jewelry or glasses are not compatible with these typesof emitter/detector systems. Additionally, form factors such as glassesare not possible because head shapes variation is too great to ensurethat the light emitted from the light emitting diodes will reflect backinto the detector from the skin once distance starts to exceed 1-2 mm,non-withstanding the risk of saturation by side light.

Therefore, it would be desirable to provide a system and method thatovercomes the above.

SUMMARY

In accordance with one embodiment, a device to extract physiologicalinformation is disclosed. The device has at least one laser emitter. Atleast one optical detector is provided to detect a change in opticalpower absorption. The at least one laser emitter and the at least oneoptical detector are wire bonded into a chip scale module.

In accordance with one embodiment, a device to extract physiologicalinformation is disclosed. The device has a processor. At least one laseremitter is coupled to the processor. At least one optical detectordetects a change in optical power absorption and is coupled to theprocessor. A passive optical device directs light beams from the atleast one laser. A lenslet collimates and directs the light beams fromthe one or more laser emitters at one or more different angles.

In accordance with one embodiment, a device to extract blood chemistryinformation is disclosed. The device has a means by which to measurelight in the approximately 9.5 um and 10.4 um range and emitters all ofwhich may be tunable. An example is a 9.5 um QCL and a 10.4 um DFB QCLemitter. Detectors may be a HgCdTe photodetector or a tunable detectorsuch as a MOEMS fabry-perot interferometer. The at least one detectordetects at least one of thermal infrared waves or radiation resultingfrom excitation by the 9.5 um QCL and a 10.4 um DFB QCL. Differences inthe measurements may be used to measure alcohol, glucose/glucogens,keytones or other blood chemistry.

BRIEF DESCRIPTION OF THE DRAWINGS

The present application is further detailed with respect to thefollowing drawings. These figures are not intended to limit the scope ofthe present application but rather illustrate certain attributesthereof. The same reference numbers will be used throughout the drawingsto refer to the same or like parts.

FIG. 1 is an exemplary block diagram of device to extract physiologicalinformation from a user in accordance with one aspect of the presentapplication;

FIG. 2 is an exemplary device to extract physiological information froma user in accordance with one aspect of the present application;

FIG. 3 is an exemplary laser emitter array used in the device inaccordance with one aspect of the present invention;

FIG. 4 is an exemplary lenslet used in the device in accordance with oneaspect of the present invention;

FIG. 5 is an exemplary lenslet used in the device in accordance with oneaspect of the present invention;

FIG. 6A-6B show reflected light signals received by the device inaccordance with one aspect of the present invention;

FIG. 7 shows wavelet processed reflected light wave signals includingmotion artifact rejection in accordance with one aspect of the presentinvention;

FIG. 7 is an exemplary device placed within a glasses frame inaccordance with one aspect of the present invention; a

FIG. 9 is an exemplary device placed within a watch band/bracelet inaccordance with one aspect of the present invention;

FIG. 10 is an exemplary device placed within a piece of jewelry inaccordance with one aspect of the present invention;

FIG. 11 is an exemplary device placed within an oral appliance inaccordance with one aspect of the present invention;

FIG. 12 is an exemplary multiplexed transconductor used in the device inaccordance with one aspect of the present invention;

FIG. 13 is an exemplary quadratic converter used in the device inaccordance with one aspect of the present invention;

FIG. 14 is an exemplary two chip scale devices placed within a glassesframe in accordance with one aspect of the present invention; and

FIG. 15 is an exemplary flow chart showing operation of a processor usedin the device in the device in accordance with one aspect of the presentinvention.

DESCRIPTION OF THE APPLICATION

The description set forth below in connection with the appended drawingsis intended as a description of presently preferred embodiments of thedisclosure and is not intended to represent the only forms in which thepresent disclosure can be constructed and/or utilized. The descriptionsets forth the functions and the sequence of steps for constructing andoperating the disclosure in connection with the illustrated embodiments.It is to be understood, however, that the same or equivalent functionsand sequences can be accomplished by different embodiments that are alsointended to be encompassed within the spirit and scope of thisdisclosure.

The present disclosure discloses a device to extract physiologicalinformation from a user which utilizes laser emitters instead of lightemitting diodes. The device may contain various other components todirect the light from the laser emitters and to send multiple beamangles out to ensure some of the beams will reflect back into thedetector.

Referring to FIGs., a device 10 to extract physiological informationfrom a user is shown. The device 10 uses laser emitters 12 instead oflight emitting diodes. The laser emitters 12 may emit a green laser,infrared laser or the like. The laser emitters 12 may be Quantum CascadeLasers (QCL), distributed feedback (DFB) laser or the like includingtunable lasers. In accordance with one embodiment, a 9.5 um Fabry-PerotQCL or equivalent wavelength and a 10.4 um DFB QCL or equivalentwavelength are used. The laser emitters 12 may be a vertical-cavitysurface-emitting laser (VCSEL) 12A. VCSELs 12A are a type ofsemiconductor laser diode where light beam emission is perpendicular tothe surface of the wafer. Alternately, or in addition to, the laseremitter 12 may be a side emitting laser 12B where the light beam mayemit from surfaces formed by cleaving the individual chip out of a wafersuch as a side emitting green laser or the like. The laser emitter 12maintain a much tighter beam compared to LEDs and thus may be used atgreater distances than LEDs. In general, the laser emitter 12 may be anarray of laser emitters 12C as shown in FIG. 3. In accordance with oneembodiment, the laser emitters 12 may be tunable laser emitters whosewavelength of operation may be tunable over a desired wavelength range.Similarly, the detectors may be tunable detectors whose wavelength ofoperation may be tunable over a desired wavelength range.

The laser emitters 12 may be coupled to a passive optical component 14.The passive optical component 14 may be used to direct the light beamemitted by the laser emitters 12. The passive optical component 14 maybe devices such as a prism, cylinders, mirrors or similar devices usedto direct light beams. The laser emitters 12 may be coupled to a lenslet16. The lenslet 16 is an array of small lenses located in the sameplane. The lenslet 16 may be used to collimate the light beam emitted bythe laser emitter 12 and to send out multiple light beam angles out toensure some of the light beams will reflect back into a detector 18 bythe topologies of many different temples, wrists, chests or other skinareas as may be seen in FIG. 5.

By having the laser emitters 12 illuminate the skin of the user, thedetector 18 can measure changes over time in the optical power of thelight beam reflected back which provides information such asphotoplethysmogram heart information. Alternatively, a processor 22 maymeasure differences in the amount of light absorbed at differentwavelengths. For example, alcohol content in blood may be measured bythe difference between light absorbed at 9.5 um vs that at 10.4 um. Aprocessor 22 may then be able to analyze this information to extractphysiological information from the user. The processor 22 may calculatethe change in optical power as light absorption varies with blood flowor excitation frequency through arteries and veins to monitor changes inblood flow, heart rate, oxygenation, blood alcohol content and the like.The processor 22 may use wavelet processing and machine learning toextract signals of interest from noise and motion artifacts without thedisadvantages of frequency based filtering which tend to damage thesignal of interest and struggle to separate other physiological sourcessuch as EMG or movement (see FIG. 5A-6). The processor 22 may have atransmitter 34. The transmitter 34 may be used to wirelessly transmitdata from the device 10 to a device 36. The device 36 may be used toread and display the data collected and calculated by the device 10. Thedevice 36 may be a smartphone, tablet or similar device. In accordancewith one embodiment, Bluetooth standards may be used for transmittingthe data from the device 10. The device 10 may have a power source 38.The power source 38 may be a battery or the like used to power thenon-passive devices.

To allow the laser emitters 12 to be placed in close proximity andwithout optical separation the device 10 uses a photodetector 18A as thedetector 18. The photodetector 18 may be silicon detector, an HgCdTephotodetector or tunable IR filter detector such as aMicro-Opto-Electromechanical System (MOEMS) fabry-perot interferometer.HgCdTe or mercury cadmium telluride is useful for infrared detectionbecause of: (1) Adjustable bandgap from 0.7 to 25 μm; (2) Direct bandgapwith high absorption coefficient; (3) Moderate dielectric constant/indexof refraction, (4) Moderate thermal coefficient of expansion and (5)Availability of wide bandgap lattice-matched substrates for epitaxialgrowth.

The photodetector 18A is configured to block side light. Thephotodetector 18A may include on chip side light blocking 18B, lightpipe 18C, anti-glare/anti-refraction coating 18D, on chip lensing andother means to reduce the incidence of side light being gathered and toreduce distortion. Side light blocking 18B may be edging or the likeformed around the photodetector 18A to prevent side light from enteringthe photodetector 18A, light pipes 18C which only allow light verticallyto fall upon the photodetector 18A, one or two layers of on chip lensingand anti-glare/anti-refraction coating reduce the incidence of sidelight being gathered and to reduce distortion.

Using the above, the device 10 may be utilized more than 1-2 mm from theskin without saturating. FIG. 6A-6B, show the reflected light signalreceived when the device 10 is 7 mm away from the skin of the user. FIG.6A show the raw light signal reflected back to the device 10 while FIG.6B shows the extracted filtered signal. As one can see, even at 7 mmaway, the device 10 is able to receive and read the reflected lightsignal.

By being able to receive the reflected light signal from greaterdistances, the device 10 may be used in different form factors andapplications. For example, the device may allow uses such as, but notlimited to: i) glasses 50 measuring heart rate or creating aphotoplethysmogram (PPG), blood alcohol, glucose and glucogens,peripheral capillary oxygen saturation (SPO2), ketones, respiration,diet, and the like from the temple of a user as shown in FIG. 8; ii)bands/watches 60 which may be worn loosely FIG. 8; iii) jewelry such asnecklaces 70 (FIG. 10), rings or ear rings which may be worn loosely andrequire small electronic assembles; iv) clothing and apparel which maybe worn loosely; v) information may be extracted from within the mouthby coupling to an oral appliance 80 as shown in FIG. 10; vi) skin cancermay be detected using measured optical information compared against adatabase of such information from by a machine learning algorithm; andvii) compatibility of a person's skin with different cosmetics may beprovided by comparing the optical information compared against adatabase of optical information favoring different cosmetic products bya machine learning algorithm; vii) optical detectors focused on the UVbands can measure and time the hazards of damaging sun exposure; viii)in combination with these optical detectors an ECG detector elsewhere onthe body may be combined with the optical information to measure pulsewave velocity, arterial stiffness and these may be converted into bloodpressure; ix) cardiac and capillary based authentication oridentification information may be extracted. By taking the time betweenthe electrical ECG peak current and the fastest derivative of the PPGwaveform (the time the heart pushes the blood to the time it arrives anddividing by the distance from the heart to the point of measurement, weget Pulse Wave Velocity (PWV). PWV is the velocity at which the arterialpulse propagates through the circulatory system. PWV may be used as ameasure of arterial stiffness and may have a correlation withcardiovascular events and an indicator of target organ damage.

As may be seen in the FIGs., to further reduce size of the device 10 ahybrid substrate and wire bonding techniques may be used where the laseremitters 12, passive optical component 14, processor 22 and othercomponents may be wire bonded directly to the substrate to avoid typicalplastic, ceramic or plastic packaging area spacings. Using thesetechniques, modules of significantly less than 5 mm thick and less than3×3 mm in surface area may be constructed. The use of laser emitters 12may allow very thin packaging by eliminating the optics normallyrequired by LEDs. Laser emitters 12 such as IR VCSELs 12A for exampleare available with multiple emitters as shown in FIG. 3 which might emita +/−17° beam which may be collimated by the lenslet 16 designed tointerface to a multi-element laser die.

By creating device 10 using wire bond techniques, typical called chipscale modules or multi-chip modules, with the side light blockingphotodetector 18A and placing the laser emitters 12 next to the detector18 it is possible to minimize module size compared with solutions whichmust separate emitters from the detector, and to make thinner modulescompared to those utilizing LED emitters. These modules may use “globtop” opaque materials to block light over active components such astransconductors, op-amps, gain devices or multiplexers and the entireassembly may be encapsulated by a transparent coating material formechanical resilience and waterproofing or optical components may be“glob topped” with a transparent coating. Additionally, physiologicalinformation can be extracted from more than 1-2 mm away from the module.Combining this with a processor 22 capable of processing wavelet andother information allows extraction during motion and in real worldenvironments where noise is present. Finally, coupling the device 10 toa portable form factor such a band or glasses and operating them from abattery allows the device 10 to be widely and convenient to used.

In addition, multiple laser emitters 12 or detectors 18 might be usedemitting and detecting different wavelengths. If multiple detectors 18are used, to couple these detectors 18 to a transconductor 26, amultiplexer 28 may be used as shown in FIG. 12. The transconductor 26may be used to generate a voltage signal proportional to the reflectedlight signal received. The transconductor 26 might have a programmablegain 28 or might have a fixed gain and be followed by a voltage gaindevice. The output of the transconductor 26 or voltage gain means mightin be coupled to an A/D converter for compatibility with digitalprocessors. Current drivers 30 may also be used which provide aprogrammable current source 32 for ensuring the laser emitters 12 areworking in the lasing region of operation and further are producing thecorrect amount of light. These drivers 30 may pulse the laser emitters12 to reduce power consumption and heat. A DC/DC converter may beincluded in the chip scale module to generate the power rails for theICs and the LEDs. This DC/DC may be dynamically controlled by theprocessor 22 so that voltage levels are only generated when required.For example, an ARM microcontroller may need only 1.6V for generalcomputation but must be increased to 2.4V when outputting a DAC value orreading using an ADC. A green laser may require 6V to operate but onlyfor a short time. To minimize components sizes the DC/DC converter mayutilize a quadratic converter topology 70 as shown in FIG. 13. Thisdevice 10 may be controlled by an intelligent processor 22 to implementan algorithmic methodology as shown in FIG. 15. The system may alsoinclude a frequency-based filter to bandpass the response of interestbefore utilizing the wavelet processing means. The overall wire bondedchip scale module might appear similar to that shown in FIG. 2.

Two or more chip scale devices may be used where the lenslet 18C directslight to the user's skin such that it may reflect from the skin and bedetected by the photodetector 18A on the second module as shown in FIG.14. For example, on the temple 42 of glasses 40, the device 10 may beformed of two modules 44A and 44. The two modules 44A and 44B may bespaced apart such that module 44A could light up the temple 46 of theuser from one side and be picked up by the module 44B or vice versa toincrease the area that is illuminated and the chance of one of thelenslet beams reflecting from the skin into the other photodetector 18Ais increased.

Many of the methods described in the text above may be extended toextract physiological information from animals. For example, a dog orcat collar or harness might utilize these methods to extract heart rate,diet or health related information from those animals or an ear sensoron a cow or horse might help separate sick animals from the rest of theherd by looking at their HRV and heart rate or SPO2 (stress, fatigue,sickness, blood oxygen, respiration, etc.).

The foregoing description is illustrative of particular embodiments ofthe application, but is not meant to be a limitation upon the practicethereof. The following claims, including all equivalents thereof, areintended to define the scope of the application.

What is claimed is:
 1. A device to extract physiological information comprising: at least one laser emitter; and at least one optical detector detecting at least one of a change or difference in optical power absorption; wherein the at least one laser emitter and at least one optical detector are wire bonded into a chip scale module.
 2. The device of claim 1, comprising a passive optical device directing a light from the at least one laser, the passive optical device configured into the chip scale module.
 3. The device of claim 1, wherein the at least one laser emitter is one of a VCSEL or side emitting laser.
 4. The device of claim 2, wherein the passive optical device is one of a prism, cylinder or mirror.
 5. The device of claim 1, comprising a lenslet, the lenslet collimates and directs light from the one or more laser emitters at one or more different angles.
 6. The device of claim 1, wherein the at least one optical detector is a photodetector, the photodetector having at least one of: side blocking edging and light tubes directing reflected light to the photodetector.
 7. The device of claim 1, comprising: a passive optical device directing a light from the at least one laser; and at least one of: side blocking edging and light tubes directing reflected light to the at least one optical detector, wherein the passive optical device and at least one of: side blocking edging and light tubes allowing the at least one laser emitter and at least one optical detector to be co-located in a single window.
 8. The device of claim 1, wherein the device is coupled to a temple of an eyewear.
 9. The device of claim 1, wherein the device is coupled to one of jewelry or an oral appliance to extract physiological information from distances greater than 2 mm.
 10. The device of claim 1, wherein the at least one optical detector is a photodetector, the photodetector monitoring at least one of variations or differences in optical power reflected from the user to determine at least one of: change in blood flow, heart rate, oxygenation, blood alcohol level, keytones, glucogens and other body readings.
 11. The device of claim 1, comprising: a plurality of optical detectors, wherein the plurality of optical detectors are photodetectors; a transconductor coupled to the plurality of photodetectors to generate a voltage signal proportional to a reflected light signal received.
 12. The device of claim 11, comprising a multiplexer coupled to the transconductor.
 13. The device of claim 11, comprising a programmable current driver coupled to the at one laser emitter.
 14. The device of claim 1, comprising a transmitter wirelessly transmitting data from the device.
 15. A device to extract physiological information comprising: a processor, at least one laser emitter coupled to the processor, at least one optical detector detecting at least one of a change or difference in optical power absorption coupled to the processor; a passive optical device directing light beams from the at least one laser, and a lenslet collimating and directing the light beams from the one or more laser emitters at one or more different angles.
 16. The device of claim 15, wherein the at least one laser emitter, at least one optical detector and the passive optical device are wire bonded into a chip scale module.
 17. The device of claim 15, wherein the passive optical device is one of a prism, cylinder or mirror.
 18. The device of claim 15, comprising: a plurality of optical detectors, wherein the plurality of optical detectors are photodetectors; a transconductor coupled to the plurality of photodetectors to generate a voltage signal proportional to a reflected light signal received; and a multiplexer coupled to the transconductor.
 19. The device of claim 15, wherein the at least one laser emitter is a tunable laser emitter.
 20. The device of claim 15, comprising a transmitter wirelessly transmitting data from the device.
 21. The device of claim 15, wherein the photodetector is one of an HgCdTe photodetector, a Micro-Opto-Electromechanical System (MOEMS) fabry-perot interferometer, or other tunable detector.
 22. The device of claim 15, wherein the processor uses wavelet processing and machine learning to extract signals from noise and motion artifacts.
 23. A device to extract blood chemistry information comprising; a 9.5 um QCL; a 10.4 um DFB QCL; at least one HgCdTe photodetector or MOEMS fabry-perot interferometer, and wherein said at least one photodetector detects at least one of thermal infrared waves or radiation resulting from excitation by the optical emitters to determine or correlate blood chemistry.
 24. The device of claim 23, comprising: a passive optical device directing light from the 9.5 um QCL and the 10.4 um DFB QCL; and at least one of: side blocking edging and light tubes directing reflected light to the at least one HgCdTe photodetector or MOEMS fabry-perot interferometer; wherein the passive optical device and at least one of: side blocking edging and light tubes allowing the 9.5 um QCL and the 10.4 um DFB QCL and at least one HgCdTe photodetector or MOEMS fabry-perot interferometer to be co-located in a single window.
 25. The device of claim 1, wherein the at least one optical detector detecting the change in optical power absorption at distances greater than 2 mm. 